WATER-SOLUBLE PHENOLIC-COMPOUNDS OF THE MARINE PHANEROGAM POSIDONIA-OCEANICA IN A MEDITERRANEAN AREA COLONIZED BY THE INTRODUCED CHLOROPHYTE CAULERPA-TAXIFOLIA

Unbound phenolic compounds of leaves of the marine phanerogam Posidoni a oceanica (L.) Delile from an area colonised by the introduced chloro phyte Caulerpa taxifolia (Vahl) C. Ag. have been investigated and thei r concentration assessed using high performance liquid chromatography (HPLC). Leaves of the colonised area exhibited high maximum values of phenolic contents in comparison with a reference area. Nonetheless, be cause of the high variability of the values, further studies will be n eeded to confirm that P. oceanica plants are producing unbound phenoli c compounds in reaction to growth of C. taxifolia. Ferulic acid, phlor idzin, phloroglucinol, p-anisic acid, acetosyringone, sinapic acid, ph enol, p-hydroxybenzoic acid, p-coumaric acid and cinnamic acid represe nt more than 95% of the mean relative concentration of phenolic compou nds measured. Several of these compounds had not hitherto been reporte d in P. oceanica.